At the age of ten, Tsiolkovsky became almost totally deaf due to scarlet fever. Consequently, he spent much time alone, but his father, recognizing his son's potential, encouraged his interests in math and physics. At the age of twenty-two Tsiolkovsky became a teacher, but he also continued to pursue his own experiments in physics and invention. His interests extended to airshi s and he developed the first wind tunnel in Russia to experiment on how much friction a metallic plane could generate at a certain speed.

In 1895, he first mentioned space travel in an article that he fully expected never to be published. It was, however, and thoughts of travel in space began to dominate him. By 1898, he completed a preliminary study of space travel and outlined many of the basic concepts now taken for granted by scientists. He proposed that humans could only enter space in a sealed cabin with oxygen reserves and air purification devices. He also knew that rockets could be the only means of propulsion in empty space because, unlike conventional engines, they did not rely on oxygen for combustion. Realizing that a rocket powerful enough to carry humans into space needed fuel with a higher exhaust speed, he advocated liquid fuels such as kerosene as opposed to the solid fuels then being tested by engineers. His theories in this regard predated the research of Robert Goddard.

Tsiolkovsky's ideas were initially dismissed by the Russian scientific community. However, following the October Revolution, the Communist government began to look more closely at his work and in 1921 awarded him a pension, allowing him to concentrate fully on his studies. Dr. Jakov Perelman, a writer and editor, helped to popularize Tsiolkovsky's ideas and by the mid-1920s Tsiolkovsky had garnered international attention. He also based a novel, Outside of Earth, on his research, which told of a journey through space, furthering his reputation among the general public.

In his later life, Tsiolkovsky was given many honors. His seventy-fifth birthday prompted glowing tributes in Soviet papers and honors from the Communist government. Following his death, the launching of Sputnik 1 was timed to coincide with the one hundredth anniversary of his birthday, but missed by twenty-nine days. Nevertheless, their efforts affirmed Tsiolkovsky's belief that "the Earth is the cradle of the mind, but one cannot live forever in the cradle."